Holy shit. I mean his wife played the prime minister in that one episode, but I never expected him to come back since I heard he was one of the actors who doesn't want to come back to Sentai (kinda like Joe Odagiri kind of thing) so this is a really huge surprise!

I think his agency had more authority than him in his decision not to return to Sentai. An actor is basically an agency's employee, so everything he does must align with the agency's decision. Perhaps he now works in a new agency?